Alun Morgan, 81, was evacuated to Wales during the Second World War and during his time there he never picked up the native tongue.

His wife Yvonne was the only person who could understand him and had to translate for doctors.

Mr Morgan, from Bathwick, Bath, Somerset, told the Bath Chronicle: "I don't remember anything from the time of my stroke. But gradually I started speaking a few words in Welsh.

"This was strange because I'd not lived in Wales since I was evacuated there during the war."

Doctors have diagnosed Mr Morgan with aphasia, a form of brain damage that causes a shift in the brain's language centre.

The most common cause of aphasia is stroke, but gunshot wounds, blows to the head, other traumatic brain injuries and brain tumours can also cause aphasia. It can also result in a disorder known as Foreign Accent Syndrome, which causes a sudden change to speech so that a native speaker talks with a foreign accent.

Researchers at Oxford University have found that patients with Foreign Accent Syndrome have suffered damage to tiny areas of the brain that affect speech.

The result is often a drawing out or clipping of the vowels that mimic the accent of a particular country, such as Spain or France, even if the sufferer has limited exposure to that accent.

The syndrome was first identified during the Second World War when a Norwegian woman suffered shrapnel damage to her brain and developed a strong German accent.